Forces…

change the motion of objects in predictable ways.

Forces change motion

Now you will learn: What a force is

How unbalanced forces change motion

Newton’s first law

ForceA force is a push or a

pull

Types of Forces (3)

1. Contact force When one object pushes or pulls by touching

another object, the first object is applying a contact force to the second

Types of Forces

2. Gravity The force of attraction between two masses

Types of Forces

3. Friction A force that resists motion

Net Force

Overall force acting on an object

- A net force of 0 is balanced

- Motion does not change

Net Force

Unbalanced forces - Change motion

Newton’s First Law

Things keep doing what they’re doing

Objects at rest remain at rest, and objects in motion remain in motion with the same velocity, unless acted upon by an unbalanced force

Inertia Is it easier to push or pull a full shopping cart or an

empty one?

Inertia – resistance of an object to change the direction or speed of its

motion

Summary

Force- a push or a pullNet force- balanced and unbalanced3 types of forces Contact, Gravity, FrictionNewton’s first lawInertia